Nissan P155b-00 — Free Forever

DTC: P155B-00
Manufacturer: Nissan
Component: Engine Control Module (ECM) / Variable Valve Timing (VVT) system
Typical Description: "Electric Intake Valve Control Actuator Circuit Performance / Bank 1" or similar (depending on model).

Replacement Procedure (General - Confirm for Your Model)

  1. Safety first: Let the engine cool completely.
  2. Drain coolant: Place a pan under the radiator petcock. Drain into a container.
  3. Disconnect battery: Negative terminal first.
  4. Remove components for access: This may involve removing the air intake duct, engine cover, or alternator depending on the engine.
  5. Unplug electrical connector from the bypass valve.
  6. Remove coolant hoses attached to the valve. Use pliers to loosen spring clamps. Be prepared for residual coolant.
  7. Unbolt the valve from the engine block (usually 2–3 bolts).
  8. Clean the mounting surface on the engine. Remove old gasket material.
  9. Install the new valve with a new gasket or O-rings. Torque to factory spec (typically 8–12 Nm).
  10. Reconnect hoses and electrical connector.
  11. Refill with coolant and bleed the system: Run the engine with the heater on max, radiator cap off, until no bubbles appear.
  12. Clear codes with a scan tool. Test drive for 10–15 minutes. Verify that P155B-00 does not return.

Step 5 – ECM Command Test (Active Test)

  • Using a bidirectional scan tool, command the actuator from 0% to 100% while observing actual position response.
  • If commanded position does not match actual, suspect actuator or mechanical binding.

Cost of Professional Repair

| Service | Estimated Cost (USD) | |---------|----------------------| | Diagnostic fee | $100 – $150 | | Coolant bypass valve (OEM) | $120 – $250 | | Coolant & supplies | $30 – $60 | | Labor (1.5 – 2.5 hours) | $150 – $300 | | Total at dealership | $350 – $650 | | Total at independent shop | $250 – $450 | | DIY cost | $150 – $300 |

Note: Prices vary by region and model year. V6 engines often require more labor due to tighter access. nissan p155b-00

Likely Causes

  1. Faulty IPM / Inverter assembly (internal current sensor failure)
  2. Wiring harness issues between IPM and ECM (corrosion, bent pins, loose connection)
  3. ECM software glitch (rare; may require reprogramming)
  4. 12V battery or DC-DC converter instability (on hybrids)

Is There a Technical Service Bulletin (TSB)?

Nissan has acknowledged cooling system valve issues on several models. For example, NTB12-055 and NTB16-085 cover certain Rogue, Altima, and Sentra models with P155B-00-related symptoms. These TSBs often prescribe a software update and/or valve replacement.

Check with a Nissan dealer using your VIN to see if your vehicle qualifies for a warranty extension or free repair—especially if you are under 80,000 miles. Replacement Procedure (General - Confirm for Your Model)

Symptoms:

  • Engine Light: The check engine light (CEL) will illuminate on the dashboard.
  • Performance Issues: The vehicle might exhibit performance problems, such as stalling, hesitation upon acceleration, or reduced engine power.

Decoding the Nissan P155B-00 Code: Causes, Symptoms, and How to Fix It

If you own a modern Nissan vehicle—especially models like the Rogue, Altima, Sentra, or Pathfinder—and your check engine light has just illuminated, you might be staring at a code that reads P155B-00 after a scan. Unlike common oxygen sensor or misfire codes, this one often leaves drivers and even some novice mechanics scratching their heads.

So, what exactly is Nissan P155B-00? Is it serious? Can you still drive your car? And most importantly, how much will it cost to fix? Safety first: Let the engine cool completely

In this complete guide, we will break down every aspect of the P155B-00 code, from its technical definition to step-by-step diagnostic and repair procedures.